George Fitzhugh was born November 4, 1806 in Prince William County, Virginia to an established southern family in financial decline. His physician father, also named George Fitzhugh, and his mother, Lucy Stuart, would later struggle as small-scale planters when the family moved to a plantation near Alexandria, Virginia. Young George was then six years old. Though he attended a local field school, Fitzhugh was largely self-educated. In 1829 he married Mary Metcalf Brockenbrough and moved near Port Royal, Virginia, where he had obtained a small plantation through marriage, and practiced law. Fitzhugh subsequently worked as a law clerk in Washington, D.C. (1857-1858) at the office of Attorney General Jeremiah Sullivan Black in the land claim department. Relocating to Richmond in 1862, he also clerked for the Confederacy's Treasury Department. Following the Civil War, Fitzhugh was appointed a judge in the Freedman's Court (part of the Freedman's Bureau) but left in 1866. Despite later publications in De Bow's Review (in 1867) and Lippincott's Magazine (in 1869 and 1870), George Fitzhugh's postbellum life, like the lives of other proslavery apologist writers, was characterized by relative obscurity. Shortly after his wife's death in 1877, Fitzhugh retired to Frankfort, Kentucky to live with his son. Two years later, in 1880, he moved near his daughter's residence in Huntsville, Texas, where he died July 30, 1881.

A vocal slavery advocate, George Fitzhugh's first publication was a pamphlet titled Slavery Justified (1849), a text reprinted as an appendix in his 1854 Sociology for the South; or, The Failure of Free Society. During an 1855 visit to Boston, Massachusetts and New Haven, Connecticut, Fitzhugh gave public lectures and engaged in lively debates with northern abolitionists on slavery. Yet he remained convinced that slavery was a rightful, necessary form of labor and that southern blacks should stay enslaved. Fitzhugh likewise considered the North's failure to address the charges he and others had leveled, primarily regarding the breakdown of northern social and economic systems, as an admission of guilt or a concession revealing the "truth" of proslavery arguments.

The Richmond publisher A. Morris printed Cannibals All! Or, Slaves without Masters in 1857. Endeavoring in the preface "to treat the subjects of Liberty and Slavery in a more rigidly analytical manner," Fitzhugh charts productive classical and historical accounts of slavery and cites the Bible as evidence. Referencing the French proletariat, various Gypsy peoples, and the Irish peasantry as groups oppressed under capitalism, Fitzhugh likewise presents the poor working and factory class conditions in England as evidence that the southern institution of slavery, modeled after a pre-capitalist, feudal society, is economically justifiable. Furthermore, he argues capitalism, as practiced in Europe and the North, produces a form of moral cannibalism, replicating the master/slave dichotomy by turning capitalists (or the professional class) into masters and free laborers into exploited slaves. Within a capitalist society, the very labor and skill extracted in pursuit of profit enslaves these workers, leaving them far more disenfranchised than their slave counterparts. Specifying capitalism's many "evils," Fitzhugh notes that it encourages falsehood and hypocrisy, impedes scientific modifications of supply to meet demand, demeans labor's value and nobility, and results in the greater impoverishment of already poor peoples while augmenting the wealth of the affluent.

According to Fitzhugh, under the humane code of southern paternalism in which masters labor on behalf of their enslaved workers, African American slaves—unlike those miserable participants in free labor's "White Slave Trade"—are happy and free. They enjoy those comforts and necessities granted them under a mutually beneficial, supportive system and community. To address the charge that slavery results in immorality, namely through illicit sexual liaisons, Fitzhugh suggests that contact between the ignorant and the more enlightened acts as a natural form of education. Despite the obviously specious and racist tendencies of Fitzhugh's arguments, more recent critical scholarship has reexamined his works and their critique of modern capitalism's industrialized, mechanized society in relation to Marxism and its theoretical offshoots.